feat: SAC 0.7.4 sidebar system stats block with UI toggle

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/tests/test_ui_settings.py

@@ -0,0 +1,32 @@
+"""GET/PUT /api/v1/settings/ui"""
+
+from app.models.ui_settings import UI_SETTINGS_ROW_ID, UiSettings
+
+
+def test_get_ui_settings_default(jwt_headers, client):
+    response = client.get("/api/v1/settings/ui", headers=jwt_headers)
+    assert response.status_code == 200
+    body = response.json()
+    assert body["show_sidebar_system_stats"] is True
+    assert body["source"] == "default"
+
+
+def test_put_ui_settings_persists(jwt_headers, client, db_session):
+    response = client.put(
+        "/api/v1/settings/ui",
+        headers=jwt_headers,
+        json={"show_sidebar_system_stats": False},
+    )
+    assert response.status_code == 200
+    body = response.json()
+    assert body["show_sidebar_system_stats"] is False
+    assert body["source"] == "db"
+
+    row = db_session.get(UiSettings, UI_SETTINGS_ROW_ID)
+    assert row is not None
+    assert row.show_sidebar_system_stats is False
+
+
+def test_ui_settings_requires_admin(jwt_monitor_headers, client):
+    response = client.get("/api/v1/settings/ui", headers=jwt_monitor_headers)
+    assert response.status_code == 403